somatomammotropin

[sō-măt′ə-măm′ə-trōpĭn, sō′mə-tə-]
n.
  1. A peptide hormone biologically related to growth hormone but produced by the normal placenta and by certain neoplasms.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.